Screw-holding insert.



. AcKEnMAN.

SC E OLDIIIG IIISI-IIIT.v

l APPLICATION FILED HMI. 7. |914. v 1,137,443. Patented M1227, 1915.

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CHARLES N. ACKERMAN, F CHICAGO, ILLINOIS.

SCREW-HOLDING INSERT.

T0 all whom it may concern:

Be it known that I, CHARLES N. ACKER- MAN, a citizen of the UnitedStates, residing at Chicago, in the county of Cook and State ofIllinois, have 'invented certain new and useful Improvements inScrew-Holding Inserts, of which the following is a specification. r

My invention relates to an improved screw-holding insert, adapted forself retention in an aperture or recess, formed to receive it, in asupporting base.

One of the objects of my invention is toV provide an interiorly threadedscrew-receiving element, and a ductile bushing therefor 'adapted jointlyto coperate with the walls of a proper recess or aperture in a suitablebase to retain the screw receiving member in iXed position therein.

A further object of my invention is to provide a construction whereinthe screw receiving member may readily be set ush with the surface ofthe base, and also to provide a construction such that the screw-draftmay take effect from the extreme outwardlypresented end -of thescrew-receiving element, thereby making the structure effective intaking and holding screws ofI minimum length. l

Another object of my invention is to provide a screw receiving structurewhich will accurately seat on the bottom of the baserecess and will takea screw for its full length, unaffected by the presence of dustparticles or the like in the base recess.

A further object of my invention is to provide means for retaining theinsert in an opening against danger of rearward displacement.

Other andfurther objects of my invention will become apparent to thoseskilled in the art from the following description taken in conjunctionwith the accompanying drawings wherein I have shown a simple embodi-yment of my invention for purposes of full disclosure thereof, althoughit will be understood ,that many changes in details of constructionmight be made without departure froml the spirit of my invention, andwithin the scope of the appended claims.

In the drawings Figure l shows in extended cross sectional fashion, abase, screw receiving member, ductile sleeve, and (in elevation) ascrew. Fig. 2 shows the parts in assembled and fixed relation. Fig. 3shows, relatively, a bushing and retainer. Fig. 4

Specification of Letters Patent.

Patented Apr. 27, 1915.

Application filed March 7, 1914. `Seria1 N o. 823,199.

shows an insert being set in an open hole to be held by the bushing andretainer. Fig. 5 shows such device completely set.

In the preferred embodiment of my invention shown I provide a screwreceiving member 10 and a' ductile sleeve 11, for cooperation with thewalls of a recess or aperture 12 in a base 13 and adapted to coperatewith any suitable screw, indicated at 14. The screw receiving member 10tapers, or varies in exterior diameter, being smaller at its forward endthan at its rear end. One advantageous shape that may be given themember 10 is indicated in Fig. 1, wherein the exterior surface is doubletapered, or biconoidal, that is to say its'base portion is taperedforward rather abruptly, and near the mid-length of the insert itssurface merges into a more acute conoidal surface; such configurati onproviding the gradual forward taper 15 and the more accentuated orabrupt bottom taper 16.

The screw receiving member is provided with a central bore 18 extendingfrom end to end thereof, and open at both ends. The forward portionofthe bore is of uniform diameter and preferably screw threaded, asshown at 19. In the wider flared portion 16 of the member the `bore isenlarged, preferably fla'ringly as at 20, so that the base-end of thestructure is a narrow annulus.

For coperation with the member 10 I provide a ductile sleeve of anysuitable character, generally indicated at 11. Such a. sleevemay takevarious forms, and the parts may be made of various metals, but I preferthatthe member 10 shall be ofbrass or steel and the sleeve 11 of lead.Preferably the sleeve 11 is exteriorly of cylindrical form,substantially of equal diameter with the base of the member 10 andinteriorly it is provided with a bore 21 so that it may pass over theforward portion of the member 10. Preferably, also, I. shape the sleeve11 interiorly in substantial conformity with the exterior contour of themember 10, and make it of such normal length that when placed on themember 10 it projects beyond the forward end thereof to a slight extent.In commercial practice I prefer to wedge the sleeve slightly on themember 10, so that the two parts may be handled as a unit.

In setting the device to receive a screw, a hole or recess as 12 isdrilled in a base 13, preferably to a depth equal to the length of thescrew receiving member 10, and of diameter slightly larger than thegreatest d iameter of the insert. A sleeve 11 is then placed on themember l and the two parts arein- -serted jointly in the recess 12. Bysuitable application of pressure, (inward on the sleeve, outward on thepart or by driving the`-lead sleeve inward around the part 10,said'sleeve is setaround the member 10, expanding laterally as it iscompressed and 10 moved longitudinally, to secure an effective grip onboth the member 10 and the side walls of the recess, and thereby tosecure the member 10 in position. It is my preference that the sleeves11 be so constructed that when tightly investing the forward portion ofthe member l0 and exerting an adequate retaining grip between the member10 and the walls of the recess, its forward end shall be about flushwith the end of the screw receiving, member. Such a construction isillustrated in Fig. 2 in applied form.

It will be noted that-the construction described aifords a veryefficient receiving member for suitable screws, indicated at 14. Thebore of the screw receiving'member 10 is preferably screw threaded fromits extreme forward end so that the .screw draft may begin at the planeof the surface of the base, and the -screw employed need be no longerthan is necessary for requisite strength and effective threadengagement. A long screw may, however, be employed,- for it may extendclear to the bottom of the recess, the screw receiving vmember beingopen from end to end. It will be observed further that in the conoidalrecess 20 there is provided a certain capacitywhich inpractice isample-for the reception'of dust or foreign matter that may reside in thebase 40 recess. For' instance in drilling recesses in the slate base ofan electrical switch board or the like, more or less of the drill-dustis apt to remain in the recesses, but under such circumstances it doesnot interfere with the proper seating of the member 10 nor does itrevent a long screw from going clear home. t will be noted that theannular base of the member 10 is narrow so that it may not readily beprevented'from finding its way clear to the bottom of the recess, and ofcourse the tapering inner wall of the boreengagement tends to preventsuch packing of dust as wouldA prevent a long screw from reaching clearto the bottom of the base recess.

For inserts to be set in open holes as at 12 I prefer to use theconstruction shown in Figs. 3A to 5, employing in conjunction with a'relatively short sleeve 11 a spring-metal retainer 25 in the form of athin flat disk having a central opening 26 of diameter about that of thesmall extremity of taper 15. The annulus is preferably slit radiallyfrom its internal periphery, so as to form spring fingers 27 for easieroperation. In

setting such a device, there being no bottom for the member 10 to reston, a compression tool, as T, is used, one of its elementsscrew engagingthe member 10, and the other pressing on the disk 25 to drive it alongkthe taper 15 as the compression action of the tool sets the sleeve 12 inthe hole. The retainerV buckles, on account of the tapering form of themember 10, and so it acts as a clutch to prevent member 10 from beingdriven rear wardly out of the set sleeve.

While I have herein described in some de tail a specific structural formof my invention for fulldisclosure, it will be apparent that changes inthe structural details might be made without departure from the spiritof my invention, within the scope of the appended claims. A

Having described lmy invention, what I claim is 1. The combination of arigid, centrallyapertured screw receiving member having its exteriorsurface tapering on two different angles, and al ductile sleeveencircling the same.

2. vIn a device of the character described,

the combination of aninternally threaded -screw-receiving member,openaxially from end to end with its axial openinglthreaded at its front endand enlarged at its rear end and exteriorly increasingl in diameter.from its .front toward its rear end, and a ductile sleeve exteriorlycoperating with said member. h

3. As an -article of manufacture a screw holding insert consisting ofarigid shell, increasing in exterior diameter from one endthereof towardthe other, axially open from end to end and having the front end portionof its axial opening screw threaded and the rear portion thereof flared.

4. -As an article of manufacture a screw holding insert consisting of arigid shell, increasing in exterior diameter from one end thereof towardthe other, axially open from its axial opening screw threaded and itsrearward end enlarged beyond the diameter l of the screw threadedportion.

5. screw holding insert member having an external configuration affordedby two conoidal portions of different pitch and a central bore extendingfrom end to end thereof, a portion of the bore being screw threaded.

6. A screw holdingvinsert member having an external configurationafforded by two conoidal portions of different pitch and a central boreextending from end to end thereof, the forward end of said central borebeing screw threaded and the rearward portion thereof enlarged beyondthe diameter of the threaded portion.

7. The combination of a tapering body, a ductile sleeve thereon, and aretainer on the V body for interengaging coaction with said body and thesleeve.

8. The combination of a tapered screwreceiving member, a ductilesleeve'thereon, and a flat annular retainer to interit on the `smallerend of said member, whereby compression of the sleeve and retainer mayeX- pand the sleeve and buckle the retainer to lock the parts againstdisconnection.

9. A screw holding insert member having` being screw threaded and therearward portion thereof, lying within the conoidal portion of greatestpitch being conically enlarged beyond the diameter of the threadedportion.

10. A screw receiving insert comprising an eXteriorly tapered internallythreaded screw receiving member, a ductile sleeve thereon, and aretainer connecting the aforesaid parts to lock them against separation.

'In testimony whereof hereunto set my hand in the presence of twosubscribing witnesses. y

CHARLES N. ACKERMAN.

In the presence of- JOHN L. JOHNSON, GEORGE T. MAY, Jr.

